Field of the Invention
The present invention generally relates to a method for forming a conformal nitrided, oxidized, or carbonized dielectric film by atomic layer deposition (ALD).
Description of the Related Art
As a method for depositing an insulation film on a substrate by ALD, substitution reaction by thermal reaction, plasma reaction, or remote plasma reaction is generally utilized. However, depending on the type of deposited film and the type of starting material, a problem may occur in that film quality is degraded because reaction in grooves of a recess pattern becomes insufficient, or secondary reaction such as physical adsorption interferes with reaction, or the like. In order to resolve the above problems, raising a process temperature and conducting post-process treatment are considered to be the most effective and have been widely conducted.
The problems of the above solutions are that when a limitation is imposed on temperature, raising the process temperature may not be acceptable, and when the post-process treatment is conducted, the total duration is prolonged, and modification reaction occurs only in a surface of a film. For example, for improving film quality in grooves by controlling temperature, the process temperature often exceeds 400° C., and also the post-process temperature often exceeds 400° C., and therefore, if the process requires a process temperature lower than 400° C., it is difficult to apply the process temperature control and the post-process treatment. In view of the above, in order to improve film quality in grooves by modifying reaction between a process material and a reactant, evaluating new materials, studying the dependency of reactant gas type, and researching comprehensive reactant reactions have been conducted. However, these attempts have not resolved the problems and have not fundamentally improved film quality in grooves.
Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.